Hydraulic control means



'Aug 18, 1953 c. E. ADAMS ETAL 2,649,106

HYDRAULIC CONTROL MEANS Urignal Filed Aug. 13, 1946 2 Sheets-Sheet 1 v T88 II 87] Cecil E. Adams vBY ELA-Lis H. .Born

.4 TTORNE Y.

Aug- 18, 1953 C. E. ADAMS ET AL 2,649,106

HYDRAULIC CONTROL MEANS Original Filed Aug. 13, 1946 2 Sheets-Sheet 2 FLUID MOTOR --55 541 Lr |]/'|6O /52 55 5.048 55,0

Fl 6.5 INI/ENToRs Ce czZ EAdams BY EZZL'S horn @Oa/M d TTORNEY.

Patented Aug. 18, 1953 HYDRAULIC CONTROL MEANS Cecil E. Adams and Ellis H. Born, Columbus, Ohio, assignors to The Denison Engineering Company, Columbus, Ohio, a corporation of Ohio Original application August 13, 1946, Serial No. 690,184, now Patent No. 2,546,579, dated March 27, 1951. Divided and this application November 2, 1949, Serial No. 125,142

12 Claims. l

This application is a division of our copending application, Serial No. 690,184 filed August 13, 1946, now Patent 2,546,579, dated March 27, 195'1.

This invention relates generally to hydraulic mechanism and is more specifically directed to mechanism for controlling the operation of fluid motors.

One of the objects of the present invention is to provide a hydraulic circuit including a reversible fluid motor and control mechanism for governing the operation thereof, the mechanism functioning during operation of the motor in either direction.

Another object of the invention is to provide a hydraulic circuit having a speed control device provided with valve means operative when desired to shunt fluid iiow around the speed control device whereby the fluid motor will receive the full pump volume to effect full speed operation thereof.

A further object of the invention is to provide a speed control device equipped with spool mechanism which is responsive to the pressure drop across an orice disposed in one of the fluid lines forming a part of the circuit, the spool being effected in the same manner by the pressure drop when uid is flowing in either direction through the orifice.

A still further object of the invention is to provide a speed control device for uid motors having a casing in which a fluid control spool is mounted for move-ment, the spool being spring centered and being provided with a plurality of passages so arranged that the application of the fluid pressure at the high side of the pressure drop mentioned in the preceding paragraph to either end of the spool will cause movement thereof to dispose the passages therein in substantial registration with other passages formed in the body.

Another object of the invention is to provide a ow control device having relatively movable sleeve and spool members with cooperating grooves and passages, means being provided to vary the relative position of these elements to form a variable orice, one of the elements being movable to so increase the size of the orifice that substantially unrestricted flow therethrough will be established.

- Other objects and advantages will be apparent from the following description of one embodiment of the invention illustrated in detail on the accompanying drawings.

In the drawings:

Fig. 1 is a side elevational view of a iiuid motor provided with a gear reduction head on one end and a speed control mechanism, formed in accordance with the present invention, at the opposite end.

Fig. 2 is a detail vertical sectional view taken through the control mechanism and the lower portion of the hydraulic motor.

Fig. 3 is a detail horizontal sectional view taken through the control mechanism on the plane indicated by the line III- III of Fig. 2.

Fig. 4 is a diagrammatic View of the hydraulic circuit in which the fluid motor and ow control mechanism have been incorporated.

Referring more particularly to the drawings, numeral 20 designates the hydraulic circuit illustrated in Fig. 4. This circuit includes a fluid reservoir or tank 2|, a power-operated pump 22 for drawing iluid from the tank 2l through a line 23 and directing the same through another fluid line 24 to a four-way valve 25. This valve may be of any suitable type depending upon the mechanism intended to be controlled thereby. For convenience in illustrating, a simple fourway Valve has been shown, this valve having an inlet port 26, with which line 24 communicates, a pair of spaced work ports 21 and 28 and an outlet port 30 which is connected by a line 3l, with the reservoir or tank 2l. The valve 25 is also provided with an operating lever 32 mounted as at 33 for pivotal movement to impart longitudinal travel to a control spool 34. Through the operation of the handle 32 either of the ports 21 or 28 may be connected with the inlet 26 and the other with the outlet 30. Fluid lines 35 and 36 are connected with the work ports 21 and 28 respectively, these lines extending to spaced ports 31 and 38 in the body 4B of the speed control mechanism.

In the diagrammatic illustration shown in Fig. 4, the body 40 is provided with a central chamber 4l with which the ports 31 and 38 communicate at spaced points. This chamber 4I slidably receives a flow control spool 42 having a longitudinal socket 43 and transversely extending passages 44 and 45 spaced longitudinally of the spool. Under normal conditions, or'when the flow control is inoperative, the spool 42 will be held in the position shown by a coil spring 46 which surrounds the reduced end 41 of the spool between a pair of washers 48 also disposed on the reduced end 41. These washers are arranged to engage shoulders 50 formed in the chamber 4I, the shoulders serving as spring abutments.

Due to the arrangement of spring and washers on. the spool 42, the latter will be yieldably retained against longitudinal movementl in either direction. When the spool is positioned as shown in Fig. 4, the transverse passages d4 and 55 will be in a non-registering relation with an annular groove 5l formed in the body 40 in communi cation with the port 38, this groove 5l being connected by a line 52 with one port of the fluid motor 53, the other port of this motor being connected by a line 55 with a port 55, also formed in the body 50 of the flow control device. The port 55 communicates with the chamber 4l, the degree of Comunication being controlled by a variable orifice 56 formed in a sleeve 51 which is disposed for adjustment in the body 40. This sleeve extends to the exterior of the body l0 and is provided with a knob 56 on its outer end to effect the adjustment of the orifice.

In the operation of the mechanism thus far described, fluid from the pump may 'be caused to flow through either line 35 or 36 to effect the operation of the fluid motor 53. If line 36 is connected with the supply, fluid will flow directly to the fluid motor without obstruction. This fluid will be discharged from the motor through line 54 and will flow through the orifice 56, the interior of the chamber 5I and through line 35, valve and line 3i to tank 2i. If the knob 58 has been previously set to cause orice 56 to resist iiuid flow from port 55 to chamber 4l, a pressure drop on opposite sides of this orice will be created. This pressure drop is utilized to control the rate of operation of the fluid motor 53 by connecting a line 6B with line 54 and chamber lil at oneend of the spool d2.

In Fig. 4 the line 6i) extends to the chamber 5I at the right end of the spool 42. Since the fluid pressure in line 55 will be greater than the fluid pressure in chamber lil, spool 52 will move toward the left in opposition to the force of spring 56 to cause passages 45 to communicate with groove 5I. When such communication is established, a portion of the fluid flowing through line 36 to groove 5'! will flow through passages 55 and socket 43 to the interior of the lchamber 4I, from which this uid may ow through line 35, Valve 25 and line 3| to the tank 2l. Due to the by-passing of fluid in this manner, the rate of operation of the uid motor will be reduced, the

degree of reduction being determined by the setting of the orifice 56.

If desired, full pump volume may be supplied to the fluid' motor to effect full speed operation, Without disturbing the setting of the orifice 56, through the actuation of an on and off valve 6l which is disposed in a by-pass line 62 connecting lines and 55. This by-pass line extends around the orifice 56 and when the valve 6l is open, uid may flow from the line directly to line 35 without owing through the orifice 56; the pressure differential caused by the orifice 56 will then be dissipated permitting spring 56 to return spool 42 to its centered position wherein full pump volume will be directed to the fluid motor 53.

VIt will be noted that when lines 36 and 52 function as inlet lines the orifice 56 creates pressure differential in the outlet line for the fluid motor 53, the pressure differential being employed to move spool 52 in one direction to effect a bypassing of a portion of the fluid supply and a reduction in speed of operation. of the motor. If

the valve control lever 32 is actuated to reversethe direction of operation of the motor 53r line CII f between passages M and groove 5l.

of this spool is connected by line 60 with line 54 in which the lower pressure exists, spool 42 will move toward the right to -cause communication Fluid from the supply will then` be by-passed from the chamber 4'! through socket d3 and passages 45 to chamber lll from which it will ow to tank 2| through line 36, valve 25, and. line 3 l. It Will thus be seen that the lflow control mechanism is operative to govern the speed of the fluid motor during rotation in either direction in the same manner since the same orifice functions to produce the pressure differential and the flow control spool has equal end areas exposed to the different pressures. The fluid motor may be reversed as many times as desirable without varying the rate of rotation in either direction. l

Through the provision of the valve 6i and by` pass line 62 the now control mechanism may be cut out and the fluid motor caused to operate at full speed, when desired, without changing the setting of the orifice or the controlled speed of the motor, thus by closing valve 6l the same controlled speed may be resumed at any time.

Figs. l, 2, and 3 illustrate one embodiment of the ow control mechanism in which the variable orice and the on and o-if valve have been com-- bined, these elements being disposed in the same casing as the ow control spool. This casing designated by numeral 55, includes the ports 3T and- 38, chamber 5I, groove 5I and ports 52 and 55. Spool Il?. is disposed for movement in chamber 5i, spring 46 being connected with the spool and located in chamber extension 66 formed in a cap 67 applied to the casing 65. At one end the' casing is provided with a vertical bore 68 for the slidable reception of a plunger '10. This plunger has a socket 'Il formed in the inner end v and a spool 12 is disposed for longitudinal sliding movement in the socket 7l. Spool 'I2 is urged in a downward direction by a coil spring 'I3 disposed 'between the inner end of the spool and. the inner end of the socket 1I. This arrangement of the spring urges the plunger 'I in an outward direction, which movement is limited by the engagement of a ange 74 formed on the' plunger, with a shoulder 'I5 provided adjacent the lower end of the bore 68. Since the movement of the plunger is limited, the tendency of thev spring 'E3 to expand will urge the spool i2 downward into engagement with the inner end of an.v adjusting screw 16. the latter -being threadedly carried by a plug Tl employed to close the openk lower end of the bore 68. The adjusting screw 'l5 vcarries a knob i8 which corresponds to the knurled knob 58 in Fig. 4 and is employed to effect the adjustment of the orifice in setting the speed of operation of the motor 53 which is secure-d to the upper surface of the casing 65.

In the present illustration of the flow control mechanism the orifice Bil, which corresponds tol, the orice 56 in the control circuit shown in Fig.V 4, comprises openings 8| formed in the plunger 7U with which head `82 on spoolf'lZ' cooperates.V By adjusting s-crew 16 inwardly, head 82 Will be moved into the socket 'il to expose agreater por. tion of the ports 8l and increase the effectiye size of the orifice 85. When. the size of the orifice is increased, less fluid will be by-passed and the speed of operation of the motor will be increased. The eiective size of the orice may be reduced by threading the adjusting screw outwardly. The position of this adjusting screw may be maintained through the operation of lock nut 83.

It will be seen from Fig. 2 that the eect of the oriiice may be temporarily eliminated by depressing the plunger l a distance suiiicient to permit full ilow through the ports 8| to the socket 1I and through 'additional ports 84 to passage 85 which communicates with port 31.

From Fig. 3 it will be apparent that casing 65 is provided with a passage 60A which corresponds in function to line in the diagram of Fig. 4 by connecting port 55 with the end of chamber 4| at the right end of spool 42.

As shown in Fig. 1, the fluid motor 53 has a gear housing 86 secured to the end opposite that occupied by the flow control mechanism. This housing contains a pinion 81 which is secured to the operating shaft of the fluid motor 53, and a gear 88 disposed in meshing engagement with the pinion, the gear being secured to the inner end of a stub shaft 90 journalled in bearings 9i in the casing. It should be obvious that rotation of the motor will impart similar movement to the stub shaft 90 and that, the gear and pinion may be transposed when it is desired to operate the stub shaft at a higher speed than the rate of operation of the motor shaft.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

We claim:

1. A ow control device comprising a body provided with a pair of passages extending therethrough and a third passage establishing communication between the passages of said pair; orifice-forming means in one of said passages; a valve element in said third passage, said valve element being yieldably biased toward a position to prevent communication between the passages of said pair and movable in opposite directions from such position to establish and control such communication; and passage means for applying the pressures at opposite sides of said orifice to opposed portions of said valve element to elect its movement.

2. A flow control device comprising a body provided with a pair of passages extending therethrough and a third passage establishing communication between the passages of said pair; orifice-forming means in one of said passages; means for adjusting said orice-form'mg means to vary the size of said orice; a valve element in said third passage, said valve element being yieldably biased toward a position to prevent communication between the passages of said pair and movable in opposite directions to establish and control such communication; and passage means for applying the pressures at opposite sides of said orifice to opposed portions of said valve element to effect its movement.

3. A flow control device comprising a body provided with a pair of passages extending therethrough and a third passage establishing communication between the passages of said pair; orifice-forming means in `one of said passages, said orifice-forming means having a ported sleeve and a spool with a head cooperating with a port in said sleeve to form -an orifice; a valve element in said third passage, said valve element being yieldably biased toward a position to prevent communication between the passages of said pair and movable in opposite directions to establish and control such communication; and passage means for applying the pressures at opposite sides of said orifice to opposed portions of said valve element to effect its movement.

4. A flow control device comprising a body provided with a pair of passages extending therethrough and a third passage establishing communication between the passages of said pair; orifice-forming means in one of said passages, said orifice-forming means having a ported sleeve and a spool with a head cooperating with a port in said sleeve to form an orifice; means .yieldably urging said sleeve and spool toward predetermined relative positions, said sleeve being selectively movable in opposition to said urging means to temporarily increase the size of said orifice; a valve element in said third passage, said valve element being biased toward a position to prevent communication between the passages of said pair and movable in opposite directions to establish and control such Vcommunication; and passage means for applying the pressures at opposite sides of said orifice to opposed portions of said valve element to effect its movement.

5. A flow control device comprising a body provided with a pair of passages extending therethrough and a third passage connecting the rstmentioned passage; means in one of the passages of said pair forming an orice, iiuid ilow in either direction through such passage causing pressure diiferences at opposite sides of said orifice; a

chamber in said body communicating with the Y other passages of said pair, and connected with said third passage, said chamber having spaced shoulders; a spool with spaced ports disposed for movement in said chamber; spring means yieldably urging said spool toward a position in which the ports therein will be disposed at the outer sides of said shoulders; and passage means for applying the pressures at the opposite sides of'said orifice to the opposite ends of said spool to move the same to cause a port in said spool to move at least partly across a shoulder in said chamber.

v6. A flow control device comprising a body having a pair of passages establishing independent ow paths through the body, said body also having a chamber, one of said passages communicatng with the ends of said chamber and the other communicating `with the intermediate portion thereof; means forming an orifice in the first-mentioned passage between the points of communication thereof with the ends of said chamber; and spring-centered ported spool means disposed for movement in either direction in said chamber in response to pressure differences at opposite ends thereof `caused by said Iorifice means, the ports in said spool establishmember and a second member cooperating with said ported member to obstruct a portion of the port in said member; and a spring centered ported spool disposed for movement in either direction in said chamber in response to pressure differences at opposite ends thereof caused by said orice means, the ports in said spool establishing communication between the passages in said body when said spool is moved in either direction from said centered position.

8. A flow control device comprising a body having a pair of passages establishing independent ow paths through said body, said body also having a chamber, one of said passages communicating with the ends of said chamber and the other communicating with the intermediate 'portion thereof; means in the first-mentioned passage providing a selective orifice and by-pass therefor between the points of communication of the passage with the ends of the chamber, said means having a pair of relatively movable members, one of said members having a port and the other cooperating with the rst to partially block said port, relative movement of said members serving to vary the effective size of said port; and a spring centered ported spool disposed for movement in either direction in said chamber in response to pressure differences at opposite ends thereof caused by said oriiice means, the ports in said spool establishing communication between the passages in said body when said spool is moved in either ydirection from said centered position.

9. In a hydraulic system having a fluid pressure line and an exhaust line; means forming an oriiice in one of said lines; flow control means comprising a casing with a chamber communieating at points spaced therein with said lines; a spool disposed in said chamber for axial movement in either direction from a position obstructing the communication between said chamber and said lines, movement of said spool establishing communication between said lines through said chamber; and passages connecting the ends of said chamber with the line containing said orifice, one end of said chamber being connected with the line at one side of theorice and the other end being connected with the line at the other side of the orifice, a pressure dierential at opposite sides of the orifice causing the spool to move and establish communication between said lines through the chamber.

10. In a hydraulic system having a iiuid pressure line and an exhaust line, an orice disposed in 'one of said lines; ow control means comprising a casing with a chamber communicating at points spaced therein with said lines; a spool disposed in said chamber for axial movement in either direction from a position obstructing the communication between said chamber and said lines, movement of said spool establishing communication between said lines through 8 sa'idchamber; a by-pass line connected with the line containing said orifice and extending around the same; and an on and orf valve disposed in said by-pass line.

11. A flow control valve mechanism comprising a casing with a pair of passages extending therethrough and a chamber, said chamber communicating at one end with the first passage of said pair and at an intermediate point with the second passage; orifice forming means in said first passage; a branch passage extending from said iirst passage at the opposite side of said orifice from the point of communication of said passage with the end of said chamber to the other end of said chamber; a spool valve disposed for movement in said chamber in response to pressure differences at opposite ends thereof, said spool having ports for establishing communication between the first and second passages; arid spring means urging said spool valve toward a position to obstruct' such communication, movement of said spool axially in either direction from said position serving to establish such communication.

l2. A iiow control mechanism comprising a casing having a pair of passages extending therethrough and a pair of bores the first of which forms a part of the rst passage and the second of which communicates at one end with the rst passage and at an intermediate point with the second passage; a sleeve-'like plunger disposed in said rst bore, said plunger having an opening therein forming a part of the first passage; a spool like plunger telescoping said sleeve-like plunger, said spool-like plunger having a shoulder arranged to partially cover the opening in said sleeve, said plungers being relatively movable to completely uncover said opening; a branch passage extending from .said first passage at `the opposite side of said first bore from the point of communication of the end of said second bore with the rst passage, to the opposite end of said second bore; a spool disposed for movement in said second bore, said spool having ports; and yieldable means tending to hold said spool in a position to prevent the ports therein from establishing communication between 'the first and second passages, pressure differences at opposite ends of Said spool serving to move 'the same to establish vsuch communication.

CECIL E. ADAMS. ELLIS H. BORN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,102,865 Vickers Dec. 2l, 193'? 2,354,634 Guswold July 25, 1944 FOREIGN PATENTS Number Country Date 791,223 France Dec. 6, 1935 

